1. Field of the Invention
The present invention relates to a document processing apparatus and a preview display method that displays a preview of a document, and a storage medium.
2. Description of the Related Art
In recent years, the Print On Demand (hereinafter, abbreviated as POD) market has been expanding along with the increase in the speed and image quality of electrophotographic and inkjet digital printers. In general, POD is a service for printing electronic data with use of a digital printer, and POD enables performing relatively small-lot print jobs in a shorter turnaround time than when conventional offset printing or the like is used.
With POD, a printing method known as variable data printing (hereinafter, abbreviated as VDP) is performed, which takes advantage of the characteristic that electronic data is used. In VDP, a document is divided into a fixed portion and a variable portion. Data for the variable portion is supplied from a data source such as an RDB (Relational Database) or a CSV (Comma Separated Value) file. Here, a column (field) in the data source is associated with a variable portion in a template document, and data in that column of the data source is applied row-by-row (record-by-record), thus enabling printing slightly different content each time. Using VDP enables creating, for example, direct mail in which the provided product information changes in accordance with customer information. This kind of use method is generally considered to have a higher advertising effect than normal printing, and therefore the use of VDP has been expanding rapidly.
The system for performing variable printing is called a VDP system, and print data in the VDP system is called VDP data. Also, the application that creates VDP data is called a VDP application. The VDP application provides a user with a user interface for performing page layout. In the user interface of a normal print layout application, the user arranges objects that are to actually be printed, such as characters and images. In contrast, with the VDP application, there are cases where these objects change according to a database, and therefore page layout is performed by determining regions where objects are to be disposed (inserted), instead of arranging objects that are to actually be printed. Specifically, these regions include regions where objects that differ according to records in a database are inserted, which are called “variable regions”, and regions where the same object for a plurality of records is to be inserted, which are called “fixed regions”. Note that “record” refers to one row-worth of data in FIG. 6A, and each record is configured by a plurality of objects.
A rule can be set such that in a variable region, the object to be inserted changes record-by-record in the database. As one example of such a rule, it is possible to set a conditional branch for fields in the database, or the object itself to be inserted can be set for fields. For example, a rule can be set for a variable region such that if the value of an “age” field in a record is from 20 to 29, a photograph image for the range of 20 to 29 is disposed, and if the value is 60 or more, a photograph image for the range of 60 or more is disposed. It is also possible to reference an “address” field and dispose the character string contained therein in a variable region. In this way, the VDP application creates VDP data that associates a database with a variable region on a page.
With the VDP application, the content of the page changes according to the values of the records in the database, and therefore if there is a large number of records in the database, it is not practical to check the layout by previewing the document for all of the records. This is because previewing the document for all of the records would specifically involve the document creator checking a number of images equal to the maximum number of records. For this reason, layout checking has conventionally been performed by checking only the position of the variable region.
However, the layout cannot be sufficiently checked by checking only the positions of variable regions. This is because with this method, although the positions of variable regions can be checked, the actual print content cannot be checked, and therefore it is impossible to make revisions as with the case of performing normal on-site printing. Specifically, it is impossible to check for printed work-related problems such as sentences becoming difficult to read or images becoming not easily viewable due to the combination of sentences, images, and the like. In view of this, it is possible to preview the actual printed works, but checking the layout by previewing the document for all of the records is not practical for the above-described reasons, and thus there has been demand for various types of countermeasures.
Accordingly, a method has been conceived for reducing the number of previews that are displayed. Japanese Patent Laid-Open No. 2005-122727 discloses a method in which the number of previews that are displayed is reduced with use of statistics such as the maximum, minimum, and average size of each region when the actual objects have been disposed in the variable regions. Specifically, pseudo print data is created by disposing maximum size, minimum size, and average size objects, and using the obtained print data as preview and proof output. Also, Japanese Patent Laid-Open No. 2005-216183 discloses that in the preview function of the VDP application, the number of previews that are displayed is reduced by searching for records that have a large difference from a certain designated record, and setting the designated records and the found record as preview targets.
However, in Japanese Patent Laid-Open Nos. 2005-122727 and 2005-216183, all of the variable regions are targets for previewing, and therefore if a large number of data pieces can be set for the variable regions, the number of previews to be displayed becomes large. Also, processing for referencing the database is performed in the display of previews, and therefore the processing load increases as the number of previews to be displayed increases.